Rhizosphere Microbial Community Diversity and Function Analysis of Cut Chrysanthemum During Continuous Monocropping

Abstract

As an ornamental flower crop, the long-term continuous monocropping of cut chrysanthemum causes frequent occurrence of diseases, seriously affecting the quality of cut chrysanthemum. The rhizosphere microbial community plays an important role in maintaining the healthy growth of plants, whereas the composition and dynamics of rhizosphere microbial community under continuous monocropping of cut chrysanthemum have not been fully revealed. In this study, the Illumina MiSeq high-throughput sequencing platform was used to monitor the dynamic changes of rhizosphere microbial communities in four varieties of cut chrysanthemum during 0–3 years of monocropping, and the soil physicochemical properties were also determined. Results showed that continuous monocropping significantly increased the fungal community richness and altered the profiles of the bacterial and fungal communities, leading to variation of community beta-diversity. With the increase of continuous cropping time, biocontrol bacteria decreased, while some plant pathogenic fungi were enriched in the rhizosphere of cut chrysanthemum. FAPROTAX-based functional prediction showed that the abundance of gene related to nitrogen and sulfur metabolism and chitin lysis was reduced in the rhizosphere of cut chrysanthemum. FUNGuild-based fungal function prediction showed that plant pathogenic fungal taxa were increasing in the rhizosphere of cut chrysanthemum, mainly Acremonium, Plectosphaerellaceae, Fusarium, and Cladosporium. Continuous cropping also reduced the content of ammonium nitrogen and increased soil salinity, resulting in deterioration of soil physical and chemical properties, which, together with the transformation of rhizosphere microbial community, became part of the reasons for the continuous cropping obstacle of cut chrysanthemum.

Shifts in soil microbial diversity and functions during continuous cropping of strawberry

“…Past studies also suggested that prolonged CC could improve fungus biomass and decrease bacteria biomass, while long‐term CC of ginger might increase bacterial diversity, form bacteriostatic soil and inhibit soil sickness (Ma, Liao, et al, 2022; Yu et al, 2022). CC of chrysanthemum also promoted the fungal growth, and inhibited beneficial soil bacteria (Wang et al, 2022). Our findings indicated that CC of strawberry had resulted in a significant reduction in the diversity of bacteria and fungi, while the relative abundance of bacteria decreased more than that of fungi, leading to a significant reduction in the proportion of bacteria to fungi (Table 2).…”

“…The ecological functions of microbial assemblages are more resilient to perturbations than their structural changes, possibly due to the presence of functionally redundant species. Some guilds associated with plant pathogens in the soil rhizosphere could be significantly enriched by CC of cut chrysanthemum (Wang et al, 2022). CC also led to lead to changes in soil ecological function, weakening beneficial microbes and enhancing pathogenic fungi (Figure 4).…”

“…Soil physicochemical properties also regulate microbial responses to nitrogen, phosphorus and potassium availability during CC (Tan et al, 2021; Wang et al, 2020). A significant correlation was found between ammonium nitrogen and soil microbiota of chrysanthemum CC (Wang et al, 2022), and pH and moisture content were the driving factors shaping the soil microbiota of strawberry CC (Huang et al, 2018).…”

An optimized biofumigant improves pepper yield without exerting detrimental effects on soil microbial diversity

“…Mean values followed by different letter(s) in a column represent significant differences at p ≤ 0.05, LSD test reducing the proportion of some beneficial soil microbes, such as Bacillus, which are often negatively correlated with Fusarium [65]. This suggests that microbiota-optimized biofumigation may aid in improving crop productivity via soil nutrient enrichment and suppression of soil-borne pathogens and weeds [41,61,66].…”

Long-term continuous cropping induced phenolic acid accumulation, acidification and microbial deterioration in greenhouse-based strawberry soil

“…According to Wu et al (2018), the populations of bacteria and fungi were signi cantly altered by CC of Rehmannia glutinosa, disrupting the balance between harmful and bene cial microbial communities in the soil. CC lowers the pH of the soil, promotes fungal growth, but suppresses the growth of actinomycetes and bacteria in the soil (Wang et al 2022). The study conducted by Li et al (2019) indicated an increase in soil fungus diversity over the 4-year period, while observing a decrease in the relative richness of Arthrobotrys within the CC.…”